Fanning strip for electrical conductors



av 17, 1970 w. A. DE SMIDT FANNING STRIP FOR ELECTRICAL CONDUCTORS Filed Feb. 21, 1968 INVENTOR WOODROW A- DE SMIDT ATTORNEY 3,541,229 FANNING STRIP FOR ELECTRICAL CONDUCTORS Woodrow A. De Smidt, Whitefish Bay, Milwaukee, Wis.,

assignor to Allen-Bradley Company, Milwaukee, Wis.,

a corporation of Wisconsin Filed Feb. 21, 1968, Ser. No. 707,145 Int. Cl. H01r 13/58 US. Cl. 174-135 1 Claim ABSTRACT OF THE DISCLOSURE A device for receiving the ends of a plurality of electrical conductors and holding them in a uniformly spaced array which has a lengthwise body of a channel configuration, openings along the sides of the body through which the conductors are extended, and pins that are pressed against the conductors to deform them and hold them in place.

BACKGROUND OF THE INVENTION This invention concerns a fanning strip for electrical conductors that is useful for holding the ends of the conductors in a formed out, or spread array, so that they may be readily connected to or disconnected from a set of terminals.

In electrical control panels and other circuit wiring large numbers of terminals are frequently mounted in rows or banks to which corresponding conductors are connected. These terminals are typically part of terminal blocks with the terminals on one side of the blocks being for connection with conductors entering from outside the panel or wiring, or being for connections that are made and broken with such frequency that it is desirable to have some means of readily making and breaking the connections.

In many wiring installations the individual conductors have individual terminal lugs that are fastened in place by the terminal screws of the terminal blocks to which the conductors are connected. A typical terminal block of this nature is illustrated in US. Pat. No. 3,236,975. It can be appreciated that whenever the conductors along one side of the terminal block are removed, for such a purpose as changing a panel or substituting some part of the accompanying circuit or reconnecting to a different external apparatus, that the resulting individually loose conductors become a disorganized multitude. Reconnection becomes difficult and time consuming, and there is a strong possibility of incorrectly making the reconnections. It has, therefore, been desirable to have some means of maintaining the conudctors in proper, spread array when they are disconnected from the terminal block, so that they retain their fanned out position for easy recon nection.

A variety of specially designed male and female electrical connectors have been made and used for facilitating rapid and easy connection and disconnection of a plurality of conductors. These connectors usually take the form of plugs, and Pats. Nos. 2,762,026, 2,688,123, 2,326,327, 2,510,944 and 2,628,263 are typical of the art. These constructions become complex and expensive, and they fail to provide an adequate solution where it is desired to have the individual conductors finished with lugs at their ends which are to be connected individually to a terminal block, or the like.

SUMMARY OF THE INVENTION The present invention relates to a fanning strip for electrical conductors, and it more specifically resides in a strip having a lengthwise body with conductor support- United States Patent ing cradles at opposite sides that are spaced to receive conductors extending through the strip, together with a pin for each conductor that can be brought down tight against the conductor to retain it in place.

When the fanning strip is used, the ends of the conductors are inserted in the cradles of the strip and the ends are also dressed with lugs that can be attached to a terminal block, or the like, with a terminal screw. The pins of the fanning strip are driven down, and the result is a unitary, fanned array of conductor ends that are retained in position with respect to one another.

An example of one usage would be a machine manufacturer who terminates the ends of electrical conductors for his machine in a fanning strip that is to be connected into an electrical control panel. A corresponding terminal block is provided by the control panel manufacturer in the factory in which the panel is made. Then, at the site of use of the machine the conductors can readily be joined in the circiut. There are also numerous other applications in which the invention may he used to advantage.

It is an object of the invention to provide a fanning strip for electrical conductors for use with terminal blocks and other devices that present banks of terminals.

It is another object of the invention to retain a group of conductors in a fixed, fanned relation when they are disconnected from a circuit.

It is a further object of the invention to provide a fanning strip which will facilitate quick and easy connection of a plurality of electrical conductors to a terminal block or the like.

It is another object of the invention to provide a fanning strip which has a body of a molded insulating material arranged to position and secure a plurality of electrical conductors that have terminal lugs on one end which are adapted to be connected to the terminals of a terminal block.

It is still another object of the invention to provide a fanning strip for electrical conductors which includes integerally molded means for securing said conductors held by said strip.

The foregoing and additional objects and advantages of this invention will appear from the following description. In the description reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration, and not of limitation, specific forms in which this invention may be embodied.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a fanning strip embodying the invention with portions broken away and in section together with an associated terminal block,

FIG. 2 is an end view in elevation of the fanning strip and terminal block shown in FIG. 1 with a portion of the block broken away and in section,

FIG. 3 is a front view in elevation of the fanning strip with a portion thereof broken away and in section,

FIG. 4 is a fragmentary view on an enlarged scale of a part of the fanning strip as seen from above and in which a pin is shown prior to being depressed,

FIG. 5 is a view in cross section on the same enlarged scale of the fanning strip of FIG. 4- showing the entire section and also having the pin shown in its raised position, this view being taken on the plane 5-5 indicated in FIG. 4, and

FIG. 6 is a view in cross section of a second embodiment of the invention.

DESCRIPTION OF THE EMBODIMENTS Referring now to the drawings, the numeral 1 designates a terminal block similar to the one described in the heretofore mentioned Pat. No. 3,236,975. It illustrates a type of device with which the present invention may be employed and it includes a bank of terminal screws 2 along one side for connecting a spaced succession of conductors 3 to the block. The block 1 is particularly suited for mounting on a control panel and forming the terminals of an electrical circuit to which the conductors 3 are to be joined.

A fanning strip of this invention is designated by the numeral 4 and is seen to comprise a lengthwise body 5 made up of a flat center part or web 6 extending the full length of the body 5, and a pair of side flanges 7 that are normal to the center web 6. The flanges 7 are integral with the web 6 and are joined with the web 6 along its margins, so that the web 6 and flanges 7 can be deemed as defining a generally channel shaped configuration for the body 5.

A number of internal partition ribs 8 extend crosswise between the two flanges 7 to lend rigidity to the structure and to subdivide the channel of the body 5 into a series of compartments, one for each conductor 3. The two flanges 7 are each punctured by a succession of openings 9 that are most clearly shown in FIG. 3. As viewed from the front and back of the fanning strip the openings 9 are of a parabolic or inverted arch configuration, so that the edges of these openings define cradles 10 that can receive the conductors 3 and function to position them when the conductors are disposed in the bottom arch of the cradles. The cradles 10 are not restricted to an arch configuration, although such shape is presently preferred.

Each cradle 10 along one side of the fanning strip is directly opposite a corresponding cradle 10 on the other side, and two oppositely disposed cradles form a pair that receive the same conductor 3. The cradles 10 of a pair are also in the same compartment established by adjacent ribs 8, so that when a conductor 3 is inserted it is positioned by a pair of cradles within its own compartment insulated by partition ribs 8 from conductors held in adjacent cradles 10.

The central web 6 of the fanning strip 4 mounts a plurality of conductor securing pins 11 that are spaced along the length of the web. Each pin 11 is positioned in alignment with a pair of cradles 10, so that it is directly above a conductor 3 that is spanning the space between the associated cradles. Also, each pin 11 is positioned intermediate a pair of successive partition ribs 8, or at the ends of the fanning strip between one rib 8 and an open end of the channel configuration. Each pin 11 is displaceable in a direction normal to the surface of the central web 6, so that its movement will intersect with a span of conductor 3 extending across the space between the associated cradles -10. Depression of a pin 11 against a conductor 3 deforms the conductor, thus inhibiting withdrawal of the conductor from the fanning strip 4. In

FIGS. 2 and 3, the pins 11 are shown in a depressed or conductor securing position, while in FIGS. 4 and 5, the pins 11 are shown in a raised or retracted position prior to use for the first time.

Each conductor securing pin 11 is associated with a cavity 12 in the central web 6 and is displaceable therein. Each pin 11 includes a shaft 13 and a series of uniformly spaced splines 14 disposed lengthwise of the shaft 13, the axis of each spline 14 being parallel to the axis of the shaft.

As can be seen best in FIG. 4, the diameter of the shaft 13 of a pin 11 is smaller than the diameter of a cavity 12. In addition, each spline 14 throughout its length overlaps the rim of the cavity 12. The overlapping portion of each spline 14 is integrally connected at its base 15 to a portion of the central web 6 immediately adjacent'the rim of the cavity 12, such as illustrated in FIG. 5. With this form of integral construction of the fanning strip 4, each pin 11 is anchored in a raised position in alignment with its associated cavity 12 and extends upward from the top surface of the central web 6, prior to initial use of the strip 4.

When it is desired to secure a span of conductor 3 spanning the space between a pair of cradles 10 for the first time, the associated pin 11 is merely depressed with sufiicient force until it intersects with the conductor 3 such as indicated in FIG. 2. The integral connections between the bases 15 of the splines 14' and the central web 6 are broken because of the force applied to the outer end of the pin 11, the material of construction used in the fanning strip 4 which permits breaking of the integral connection will be described later. Because of the physical construction of a pin 11 with respect to its associated cavity 12, it can be clearly seen that depression of the pin into its cavity will result in a friction or interference fit sufliciently strong to prevent movement out of a conductor securing position unless desired and effected by force, such as by pulling out the pin 11 with a pair of pliers.

The fanning strip 4 of this invention can be formed of a suitable insulating material that is relatively rigid. Such materials can be, but are not limited to, a relatively rigid molded plastic material such as a molded nylon, a molded polyester resin, or a molded phenol formaldehyde condensation product, or materials which are considered elastomeric in nature, such as natural or synthetic rubbers or combinations thereof which may be compounded in a manner well known to those skilled in the art to provide a relatively resilient, slightly flexible structure having a hardness suitable for the application herein described.

It is a particularly advantageous feature of the invention that the fanning strip 4, including its depressible, conductor securing pins 11, can be easily molded as an integral or unitary structure according to techniques well known by those skilled in the art. The pins 11 will usually be molded to the body 5 in raised or retracted position as seen in FIG. 5. The fanning strip 4 can be manufactured to any desired convenient and economical length suitable for the intended use.

Other types of conductor securing pins 11 can be carried by the body 5 of the fanning strip 4. For example, in addition to the depressible type of pin shown in FIGS. 1-5, a threaded type of pin 16 can be used as seen in FIG. 6.

Although certain preferred embodiments of the invention have been specifically disclosed, it is understood that the invention is not limited thereto since it is expected that many variations will be readily apparent to those skilled in the art while still practicing this invention. Therefore, it is to be understood that it is intended to cover all changes and modifications of the embodiments of this invention herein specifically disclosed, as well as other embodiments not disclosed, which do not constitute a departure from the true spirit and scope of this invention.

I claim:

1. In a fanning strip for electrical conductors the combination comprising:

a one piece, molded plastic, lengthwise body for receiving a plurality of conductors along its length that includes a central web with a plurality of holes spaced successively along its length, and two side flanges depending from the lengthwise edges of the web to present a channel shaped body open along the side opposite the web;

said flanges each containing a plurality of arch like openings that extend up to and through the web, such openings of a flange being paired with the openings of the opposite flange and being aligned with said holes in said central web, whereby a conductor can be inserted through a pair of said arch like openings and extend under one of said holes;

and a plurality of conductor securing pins each having a shaft portion concentric with and of smaller diameter than one of said holes, and a series of splines running lengthwise of the shaft that have 6 an outer diameter larger than the hole with the ends 3,417,192 12/ 1968 Elm 17459 of the splines being integrally molded with said cen- 3,459,878 8/1969 Gressitt et a1 174112 tral Web, whereby a displacement of each pin can be made through its associated hole in said central FOREIGN T web into the channel of the body, so as to be de- 5 5591061 2/1944 Great Bntampressed against a conductor extending through the OTHER REFERENCES associated arch like openings to deform said con- IBM Technlcal Disclosure Bulletln, G. E. Martln, v01. fictgdilnd 1nh1b1t wlthdrawal of the conductor from 4 No. 5, October 1961 strain Relief Device.

References Cited 10 LEWIS H. MYERS, Primary Examiner UNITED STATES PATENTS A. T. GRIMLEY, Assistant Examiner 3,087,009 4/1963 Blanchet 174-135 3,265,937 8/1966 Sturdivan 174-59X US. Cl. X.R. 3,279,014 10/1966 Fischer 17465X 15 339103 

